text:
Can I fly in Europe using an FAA Statement of Demonstrated Ability (SODA)?
I want to become a airline pilot but I have Monocular vision. I have no vision in my left eye but I have good vision in my right eye. I have read that I cannot become a pilot in Europe because of this condition.
So I just want to know if I can get a Statement of Demonstrated Ability (SODA) equivalent in Europe and then become a airline pilot?
If that is not possible, then can I take an FAA medical class 1 with a SODA, and then move back to Europe and fly in European airspace and fly internationally?

FAA regulations are only going to be valid within the USA and its territories.  You will have to consult with EASA or your local regulators about their standards for medical certification and waiver requirements.

But would it be easier for me if I have a valid faa medical class 1, and is it possible to get a soda in Europe.

That is something you would have to discuss with an AME if you were seeking flight training as a lawful resident in the United States

If that is not possible, then can I take an FAA medical class 1 with a
  SODA, and then move back to Europe and fly in European airspace and
  fly internationally?

Potentially, the FAA vision requirements, require you to have 20/20 in both eyes individually (corrected or uncorrected). You can find a summary of the regulations here to pass a standard medical. However the FAA does have a special issuance for people with monocular vision which you can find more info on here

An applicant will be considered monocular when there is only one eye
  or when the best corrected distant visual acuity in the poorer eye is
  no better than 20/200. An individual with one eye, or effective visual
  acuity equivalent to monocular, may be considered for medical
  certification, any class, through the special issuance section of part
  67 (14 CFR 67.401)

This would make you eligible for a class 1 medical which would allow you to train here in the US as well as get a full FAA commercial/ATP ticket which is valid in most of the world. Bottom line is that you can become an airline pilot (at least under FAA rules) and fly international, moving back to your home country may be an issue if they don't recognize an FAA license or the airline has its own medical regulations.

But it’s possible or am I wrong and does Germany recognize faa medical rules.

@NicolaiTrampedach they should if you hold an FAA pilot certificate and operate under FAA regulations. There are lots of questions here and elsewhere online about coming to the US for pilot training then heading back to Europe for a work.

Even if I’m monocular.

@NicolaiTrampedach You should speak to a german aviation official but my understanding is that you only must comply with the regulations of the license you are trying to fly with it does not matter where in the world  you are trying to do so as long as that location recognizes the privileges of the license.

Nice, it was because there was one who said that I could only get a private license.

Or can I only get a private license or can I get a commercial.

You should be able to obtain any FAA issued license as the regulation does not seem to stipulate a medical class cap.

So I could get a class 1 and become a commercial airline pilot with a faa license and fly for a European airline in European airspace

Let us continue this discussion in chat. These are all good questions but are better suited for the chat. Some may turn into new questions here on the site as well.


text:
Which authority is responsible for RT licensing in the Netherlands?
Which authority does issue the separate RT license for pilots in the Netherlands?
I had a conversation with Netherlands CAA and they could not help me.

Hallo Daniel, welkom to Aviation.SE

The Dutch authority responsible for radio communication licenses is 'het agentschap telecom', part of the ministry of economic affairs.
More information about licensing for the aviation radio bands can be found on their website (in Dutch).

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text:
What are the rules for logging PIC time on an IFR flight plan in mostly VFR conditions with a safety pilot?
I act as safety pilot for a student who is building hours towards his instrument rating. I have my IR but am not a CFI. We typically fly VFR with him under the hood as the "sole manipulator of controls" so we can both log PIC hours.
On an upcoming long flight, I'd like to file an IFR flight plan. We expect the conditions to be VMC, but we need to plan for the possibility being routed through some patches of light IMC. Are we permitted to both log the PIC time during which we are in VMC, and then just switch off "actual PIC" duties when we enter patches of IMC (during which time I would log "actual IMC" time, and he would log nothing)? In reality, it will be the autopilot doing most of the flying.

The FAA has a legal interpretation (Walker Letter, 2011) that addresses exactly this issue, and that's what I used for this answer. We also have this question and this one that cover very similar but slightly different scenarios.

First, PIC time. Since you're instrument rated and the other pilot isn't, only you can act as PIC under IFR. So, with that in mind, when can you both log PIC time per 61.51? You didn't mention the aircraft, but I assume it's a light single that only requires one crew member.
The key point here is that operating in simulated instrument conditions is an operation that requires more than one crew member. But operating in actual instrument conditions is not such an operation.
As long as you're in VMC and assuming that your friend is under the hood, you can both log PIC time. You're acting as PIC during an operation requiring more than one crew member (61.51(e)(iii)), he's the sole manipulator of the controls (61.51(e)(i)).
But when you enter IMC, your friend continues to log PIC time as sole manipulator, however you cannot log PIC time because you're not a required crew member while operating in IMC (see the penultimate paragraph of the legal interpretation above).
Second, instrument time. The only way to log instrument time (in your scenario) is described in 61.51(g)(1) (and see this question):

(g) Logging instrument time. (1) A person may log instrument time only
for that flight time when the person operates the aircraft solely by
reference to instruments under actual or simulated instrument flight
conditions.

Assuming that only your friend controls the aircraft (manually or using the autopilot) then only he can log instrument time. If you take the controls in actual IMC then you would log instrument time but your friend wouldn't.
Third, putting it all together. Assuming that only your friend controls the aircraft throughout the entire flight and he stays under the hood while in VMC then you would log time as follows:

VMC. You: PIC (acting PIC while more than one crewmember is required). Your friend: PIC (sole manipulator), instrument (simulated IMC).
IMC. You: nothing. Your friend: PIC (sole manipulator), instrument (actual IMC)

While operating in IMC, it seems odd that the instrument-rated pilot, who is legally necessary for the plane to be flown there at all, now becomes "not required" whereas before, he was required.  Is it correct that the instrument rating is separate from the "required crewmember" status?

@RalphJ Remember that we're talking about logging PIC time here. The pilot with the IR remains acting PIC for the entire flight, regardless of flight conditions or who's controlling the aircraft. And AFAIK there's no link between an IR and being a required crewmember, it just so happens that simulated instrument flight is an operation that needs multiple crewmembers. If an aircraft's type certificate requires multiple crewmembers, they're required even under VFR.

I would like to emphasize the part that states that there is no such thing as a safety pilot in IMC.

An IR student flying in VMC with you as safety pilot - both can log PIC. But in IMC (on an IFR flight plan listing you as the pilot), the student cannot log as a pilot of any sort -because you are not a CFI.

@MikeBrass I'm not completely sure what scenario you have in mind, but the FAA interpretation I referenced says it's the reverse: the "student" logs PIC time in actual IMC and the "safety pilot" logs nothing (assuming he isn't a CFII, as you said).

@Pondlife My point was in actual IMC conditions the 'student' is not legal to be log PIC because the person in the right seat is not a CFI. If the 'safety pilot' is a CFI/CFII, then it would be fine.

@MikeBrass If the student is rated in the aircraft then he can log PIC time whenever he's the sole manipulator of the controls - including in IMC - but he can't act as PIC because he isn't instrument-rated. I'm not sure if you read the interpretation I linked to, but it explains it in more detail.

Wow, that FAA interpretation is bureaucratic idiocy at its absolute worst.

Your friend, who lacks an instrument rating, would be the sole manipulator of the controls of an aircraft conducting an operation (IFR flight). Since he is rated for the aircraft (not necessarily for IFR flight), he may log the time as the sole manipulator of the controls.
This is a frequent question, and there are numerous resources addressing it.
https://www.aopa.org/training-and-safety/learn-to-fly/legacy-pages/aviation-subject-report-logging-pilot-in-command-pic-time
Addendum #1
A plain language reading of 14CFR61.51(e)(1)(i), which states: "(e) Logging pilot-in-command flight time.
 (1) A sport, recreational, private, commercial, or airline transport pilot may log pilot in command flight time for flights-
 (i) When the pilot is the sole manipulator of the controls of an aircraft for which the pilot is rated, or has sport pilot privileges for that category and class of aircraft, if the aircraft class rating is appropriate;"
There are no other limitations which require the sole manipulator to have an instrument rating.
Furthermore, the pilot, acting as PIC, who is responsible for the safe conduct of a flight in IMC, and is rated in the aircraft, with a valid medical, and is current, is able to log time acting as PIC, whether or not they are the sole manipulator of the controls.
Therefore, the sole manipulator may log as PIC time they are the sole manipulator, and the pilot acting as PIC may also log time they are acting as PIC.
This topic frequently comes up and DPEs and Flight Instructors are fielding this question frequently. Not everyone gets it right all the time. Personally, I have had scores of instrument students take flight tests with DPEs and FAA Ops Inspectors, and I believe everyone of them has logged time in the manner the OP asks. I urge pilots to add details in their log book remarks, describing the situation and conditions, and while it might not be required to also include the name and cert # of the other pilot in shared duty flights.
Some clubs, and FBOs may have issues with who is responsible for flights, and you might consider memorializing your agreement prior to your flight. Also note that there is no reason why the acting PIC could not switch during a flight one or more times.
There are quite a few assumptions in this answer, such as there is no type certificate requiring multiple crew members, etc.
BTW, if the manipulator in this example, stays under the hood, they could continue to log as simulated instrument flight, even though the conditions are actual. Otherwise they may log instrument time, and since they are not rated, in this case, I would very strongly urge that the remarks section record the name and cert of the pilot acting as PIC, who would be required to have current instrument rating (and who could not log instrument time for that portion of the flight, or log any approaches, as they did not operate the aircraft for the approach).

I'm not sure that your comment about acting as PIC is correct for the specific scenario in this question. 61.51 lists various scenarios in which you can log PIC, but just acting as PIC by itself isn't sufficient. The Speranza interpretation states that explicitly.

If the manipulating pilot remains under the hood the acting as PIC pilot is required by regulations, and by agreement is acting as PIC, and because he is required by regulations, he may log the acting time as PIC time.

In VMC, I completely agree with you, but this question is about IMC too. I'm not sure if you read the two interpretations I linked to, but in Walker the FAA said that acting as PIC doesn't automatically mean you can log PIC: "being the PIC in this context is not a basis for Pilot A to log flight time". And the Speranza interpretation says that actual IMC is not an operation for which more than one pilot is required, therefore the acting PIC can't log time under 61.51(e)(1)(iii). So there's no way I can see that the acting PIC can log PIC during actual IMC time, unless he takes the controls.

@Pondlife.  Can aciting PIC log PIC during actual IMC, if not manipulator? I submit the following: 1. We accept that a non-instrument pilot may log time manipulating the controls, with a safety pilot, who can be acting PIC or SIC depending upon the agreement of the parties, and with some other assumptions. 2. There is no regulation which prohibits simulating instrument flight with a view limiting device, while in IMC conditions. 3. If the pilots agree that the manipulator shall fly with a view limiting device, then the rules require that there be another pilot,  CONTINUED

who by agreement may be the acting PIC, and by regulation must be the acting PIC.  4. Since the rules require the second pilot, who by necessity is instrument rated, because the first pilot is manipulating with a view limiting device, in this sample instance, both pilots may LOG pic.

Story, but relevant.  A pilot trained by another CFI-AI who I was familiar with, needed his first IPC (well back then, and instrument competency check).  We went up on a fall day, and while doing holds the conditions went actual, and then we were cleared for the approach. He was juggling plates, hearing some heavy lake effect showers wash the plane, and getting bounced around, so I didn't press getting the hood off. On the ILS I suggested he do so. He then told me he did EVERY approach with a hood on. He was comfortable, and it reduced "distractions." We fixed that behavior.

Regarding FAA LOI. I know a guy who had his ATP and CFI revoked for 9 months following to the letter a LOI.  The FAA is not bound by LOIs, and FAA attorneys will tell stories over beers about how LOIs have been incorrect. Following a LOI is great for general guidance, but on some things the FAA waffles back and forth repeatedly. AOPA's legal staff has many stories. I suggest that LOIs be utilized for guidance, and understanding, but that every pilot learn how to read and interpret regs for themselves, because in the end it is you, not a LOI who may have to defend your actions.

Well, all I can tell you (and the OP) is that your question "Can acting PIC log PIC during actual IMC, if not manipulator?" is exactly what the FAA addressed and they said no. How much weight you attach to that - or any other FAA legal interpretation - is indeed up to you.

LOIs are LOIs, but each of us should be able to interpret the regs as they apply to us.  The OP now has an opinion (or more) and a LOI to consider. It is noteworthy that the FAA did not in their letter consider the scenario that I detailed as an example.  Perhaps if there was a new request for interpretation they might have a slightly different stance.

“…the Speranza interpretation says that actual IMC is not an operation for which more than one pilot is required…”. True that, but it is an operation for which an instrument rated pilot is required!  So, by extension of that logic the IR pilot should take the controls.  Allowing the non-IR pilot to fly in IMC without acknowledging the necessity of the IR pilot as a required crewmember (safety pilot?!) is sheer lunacy...

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text:
Examples of non-direct flight tracks (ETOPS, political instability, etc.)
Flights don't always follow the great circle route (the shortest distance between two points on the globe) for a number of reasons:

Political Instability
Airspace Closures
ETOPS Limits
Geography (eg. the Tibetan plateau)
Airspace Structure
Weather
Prevailing Winds
etc.

I am trying to find flight tracks (preferrably on Flightradar24) to illustrate each of these cases. Below is an example I found of a Finnair flight avoiding Ukrainian, Russian and Afghani airspace.
I would be grateful for other examples that I can use to illustrate these cases.

Source: Own rendering using matplotlib basemap based on geodata from Finnair Flight FIN99 (12.02.2023), from https://flightradar24.com

What is your question? You seem to have answered it by listing reasons why great circle routes aren’t followed. Practically all commercial flights do not follow GC routes due to the things listed in your question. I would add that “prevailing wind” means typical wind whereas flight planning is due to the actual forecast wind aloft at various flight levels (https://dictionary.cambridge.org/dictionary/english/prevailing-wind). The jet stream changes in strength and position day to day.

"I am trying to find flight tracks (preferrably on Flightradar24) to illustrate each of these cases."
What I had hoped to find in an answer are some identifier of flights in which one of the reasons I listed (or more than one) are quite pronounced.

Here's an example from recent memory:
RSD 898
Flight 1, Flight 2
A Russian government plane has to avoid Europe to head to Washington D.C.

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What aerodynamic phenomenae can decrease the pressure gradient in Boundary Layer Ingestion?
I'm exploring a question concerning whether or not boundary layer airflow presents physical limitations that are too great for current technologies to overcome (I'm holding the position that it is in fact doable) but I've seem to only be able to find one main method of active flow control in the inlet of an embedded engine.
Specifically, pulsating air jets for active manipulation of the air ingested into the engine. As to create uniformity along any modeling 3D or otherwise for future flow sims I am using the basic frame of the Boeing BWB 450-1U concept with the proposed GE58 F2/B1 UEET turbofans.
I would like to know if there are any aerodynamic phenomena that would decrease or eliminate a pressure gradient that would naturally build up on the face of a Boundary Layer Ingestion.
As previously noted, I am aware of active control measures, but I would prefer a passive solution like vortex generators (as they present a minimal detriment in aerodynamic quality yet a significant advantage in efficient solution to the given lift problem)
P.S. I have checked all related posts/answers and none are either recent enough nor complete enough for my question in particular, so please don't disregard it as such.

Now we know what you are working on, but we don't know what you are asking. Could you please be more clear? And in case you expect a complete list of all boundary layer manipulation techniques: We are not here to write your paper.

@PeterKämpf I apologize for not being clearer and want to say that I in no way am trying to cut corners or anything. To better phrase my intent, I would like to know if there are any aerodynamic phenomenae that I haven't identified that could reduce or eliminate a pressure gradient that would build up naturally along a BLI. I want to let it be known that I could only find the air pulse as a physically and practically viable solution. It was referenced and studied in several reports; one by ERAU and two by NASA/NACA and other methods were simply too problematic for consideration.

You know what I'm just going to edit my question to better reflect my intent. Thanks @PeterKämpf for your brutally candid but constructive insight ;)

First, let me explain the context of your question: It is about a concept for a future airliner:

Boeing Blended-Wing-Body Model 450-1U, taken from NASA/CR-2006-214534.
In the artist impression above the engines are podded and sit on struts in order to achieve a uniform flow field at the intake face. However, the strut and nacelle surface area will contribute drag that could be avoided if the engines would be mounted closer to the rear fuselage. The picture below, taken from the same source, shows a CAD rendering of a possible geometry with semi-buried engines:

The disadvantage of this concept is the ingestion of boundary layer flow such that the speed profile over the intake face shows a speed gradient (BMI = boundary layer ingestion). This will result in distorted flow at the compressor and cyclic pressure variations for the compressor blades, which in turn will require a more robust and less optimized compressor geometry or run the risk of compressor stalls and early blade failure. Also, the energy loss within the boundary layer results in lower pressure recovery ahead of and inside the intake, which will increase specific fuel consumption.
Or to quote the NASA page on inlets:

As the air is brought from free stream to the compressor face, the flow may be distorted by the inlet. At the compressor face, one portion of the flow may have a higher velocity or higher pressure than another portion. The flow may be swirling, or some section of the boundary layer may be thicker than another section because of the inlet shape. The rotor blades of the compressor move in circles around the central shaft. As the blades encounter distorted inlet flow, the flow conditions around the blade change very quickly. The changing flow conditions can cause flow separation in the compressor, a compressor stall, and can cause structural problems for the compressor blades. A good inlet must produce high pressure recovery, low spillage drag, and low distortion.

The question now is: What can be done to keep the semi-buried engine concept but to avoid the intake flow distortion from boundary layer ingestion?
Solution 1:
As it turns out, the same NASA paper proposes a simple diverter ahead of the engines which is supposed to push the slow boundary layer to the side:

Solution 2:
An even better solution is to use a splitter plate; after all, the semi-buried engine has an intake very similar to the side-mounted intakes of trainer and combat aircraft. Below is an example from another subsonic aircraft, the Czech L-39 Albatros jet trainer:

Subsonic splitter plate intake on the L 39 (picture source)
Solution 3:
Less commonly used, boundary layer suction can be employed to remove the slow-moving air close to the surface and to re-establish a more uniform speed profile. Here my example is the Eurofighter EF-2000 intake, where boundary layer suction is used to remove the boundary layer that has accumulated on the splitter plate itself:

EF-2000 intake, here abused as a baggage compartment. The grid of holes is used to suck away the boundary layer.
A similar arrangement was used on the intake cone of the SR-71, but I did not find a good picture. Boundary layer suction, however, is not the kind of passive solution you desire. But it has the advantage of being adaptable to the specific flight situation.
Solution 4:
Also not passive, and not being used in existing airplanes, would be a moving surface ahead of the inlet. This has been tried with rotating cylinders at flap breaks, and there is some literature covering the topic. The moving surface will reverse the effect of the wing ahead of the intake and re-energize the boundary layer right ahead of or inside the intake.
In all cases, you need to check whether the newly incurred losses of the boundary layer manipulation will be lower than the gains in engine efficiency. I did not go into vortex generators: They might help to equalise the speed loss or at least to reduce the speed gradient towards the surface, but they incur new and intense losses all by themselves and would most likely reduce efficiency a lot. If well placed, they will reduce intake distortion, but at the price of a much reduced pressure recovery.

Wow... this was so comprehensive thank you so much @PeterKampf! However, I must have misstated my question, cuz I understand the concept of BLI, but I'm not necessarily  to the BWB 450 concept. I got it from the MANY NASA reports as the standard basis for the BLI engine, so if I wanted to do further testing it would produce data I could probably benchmark with the NASA reports. As for the splitter plates... I never thought of diversion rather than manipulation. Regardless of the design I prob wouldn't choose a supersonic frame anyways.

Sorry one more question: I'm not too well versed on diverterless supersonic inlets, but the Wikipedia page for DSI says that it could possibly divert boundary layer airflow. Given that it has supersonic applications, could the bump still provide adequate diversion of the boundary layer while introducing less form drag than splitter plates?

@Jihyun: Diverterless supersonic inlets are rather new, so I am not so familiar with the details. The Wikipedia article sounds overly enthusiastic about their merits - after all, why did designers use splitter plates for half a century, and only moved to DSI when stealth mandated it? The main difference between sub- and supersonic inlets would be the intake lip (rounded vs. sharp), because most of the boundary layer in supersonic flow is moving at subsonic speed. The bump will have less surface friction than a splitter plate, but will not nearly be as effective. What is adequate is up to you.

Right, I will probably modify my preexisting BWB model and do a CFD analysis on both. Thanks for the extra info.

Current trend... just accept it and make a fan/compressor that is capable with working in the boundary layer. NASA's latest concept on this (here is a link https://www.nasa.gov/feature/aviation-renaissance-nasa-advances-concepts-for-next-gen-aircraft) is that by ingesting the boundary layer they might need more power, but they also reduce drag. Think of it this way, an engine already needs to decelerate high speed air that is coming in, doing this wastes some energy (most is converted to pressure though), the boundary layer is already decelerated, so if it can be used, then you are not wasting energy on deceleration twice.

Yes I understand the concept man ;). Think of the issue this way, the air hitting the top of the inlet is fundamentally at a different velocity and pressure than the bottom, creating a gradient that at speed becomes unstable and triggers vibrations and more importantly stalls inside of the engine, leading to damage and possibly thrust reversal. How to fix this? According to the word of the aero-lord PeterKampf splitter plates, I previously thought air pulse jets. All this goes to say, I know what I'm talking about, this answer doesn't answer my question though... thanks for explaining anyways?

The boundary layer type of deceleration turns speed into temperature while ram effect deceleration turns it into pressure. Big difference! Super brief info on jet intake flow: Pressure = good, heat = bad, gradient = very bad.

Yes, adverse pressure gradients are bad. Yes, it is of benefit to take advantage of the velocity to pressure transfer in the ram effect. If possible however, you want to ingest as much of the boundary layer as possible to get maximum effect, and by rejecting the worst flow, you also ignore the part that has the most to gain from BLI. Even though it is harder, you want to capture as much of the boundary layer as possible, so the current goal is to make a fan blade design that can handle it. Check the last section of the link link


text:
Are there any known aircraft (experimental, otherwise) with non-fixed vertical/horizontal stabilizers?
Imagining contortions of the vertical/horizontal stabilizers and possible use cases for dodging or acrobatics, I was wondering if there were any known aircraft with such a design.

The XP-55 'Ascender', one is preserve at Kalamazoo, Mi, Air Zoo, had a fully moveable 'Canard' foreplane, not just the rear surfaces, but the whole of it.

The SR-71's rudders pivoted without any fixed leading edge, as shown:

Source

Source
The T-38 (along with many other supersonic jets of its era) had a pivoting horizontal stabilizer with no fixed leading edge:

Source
So yes, each of those features asked about can be found in production aircraft. It seems likely that some aircraft sometime even had both, although offhand I don't know which one.

For example, Sukhoi Su-57 has both.

Many aircraft use an all-moving horizontal tail—with or without an elevator.
Fighter aircraft (F-15, F-22, F/A-18, etc.) often use an all-moving tail without elevators.  This gives superb control authority.  The tool can move at 'fast rate'—as the primary control surface.
Transport aircraft (B737, A320, etc.) often use an all-moving tail with an elevator.  In this case, the tail moves very slowly on a jackscrew—it is moved for trim, with faster rate control still accomplished with the elevator.
There is also a concept called a 'free wing'.  It mounts the wing on a bearing through the aerodynamic center.  The wing is free to pivot independent of the rest of the airframe.  I am unaware of any horizontal or vertical tail that operates in a free-wing type mode.

In the light aircraft world, plenty of designs use non fixed horizontal tails, called, "stabilators" or "all flying tails" when they first came out. With unpowered controls, you need a means of driving the surface to a particular angle for trim when not holding the stick, and a simple trim tab like you'd use on a regular elevator isn't enough. For that they use an anti-servo tab, whose range of motion relative to the stabilator can be varied by the trim control.
The anti-servo tab will drive the surface to a specific incidence and hold it there, to achieve a desired main wing trimmed angle of attack. Because of the way the tab is linked to the trim actuator, any displacement from that angle causes the tab to move in opposition to the main surface movement, driving it back to its trimmed angle. For example, if the tailing edge of the stabilator moves up from its trimmed angle, the anti-servo tab moves up relative to the trailing edge, providing an opposing (anti) aerodynamic servo restoring force that returns it to its trimmed state. Hence the name.
The anti-servo tab allows you to use the same one-piece all moving surface for stabilization, maneuvering, and trim with unpowered controls. Cessna Cardinals, and the Piper Cherokee line have such horizontal non-fixed tails, among others. Since the stabilizing surface is doing double duty as the maneuvering and trim surface, somewhat less surface area is required than a fixed stabilizer/elevator.
All moving vertical surfaces are less common in General Aviation aircraft, but what springs to mind are the Zenith and Robin designs, that use a one piece all moving rudder with no fixed stabilizer, or a very small one.
The Zeniths/Robins don't use anti-servo tabs to drive the rudder to a trimmed angle; for passive yaw stability, these airplanes rely on sufficient side area of the rear fuselage to keep the aerodynamic center of the fuselage far enough aft of the center of mass to maintain a passive weathervaning tendency.

Just solo'd in a Piper Archer PA28, which has a non-fixed horizontal tai!

Stabilators are great in that the control forces can be tuned by tab gearing & surface area, etc to get the stick force behaviour you want. One downside to them is a bit of hysteresis in the trim state. It results in a bit of a "band" in steady state trim, where the system will tolerate some fraction of a degree of AOA up for down at a given trim setting. When cruising for extended periods in smooth air, you might notice the plane sort of drifts up and down within a small range if you leave it alone. I found the Pipers did that, while my old Cardinal, which had a much larger surface, didn't.

I think fully-flying control surfaces are too common to merit a mention. Especially for supersonic airplanes they are de rigeur.
But there is one design which had a variable-sweep control surface: The Beech Starship. Here, the sweep of the canard surface could be adjusted. This helped to increase canard effectiveness in case of lowered wing flaps, but I doubt that the added weight of the sweeping mechanism could really be offset by any efficiency gain in cruise. Sweeping did, however, improve forward-down visibility.
Burt Rutan first built a 85%-scale model of the design and powered it with two PWC PT-6 turboprop engines, giving it spectacular flight performance. Once the final, much larger design was done and certified, the still two PT-6 only allowed for average performance, certainly not on the level of jets with which the Starship had to compete, and became a major (if forseeable) disappointment for Beech.

Drawing of the variable sweep canard in US patent 4,641,800.
In the end, after only 11 articles had been sold, Beech scrapped the whole program and destroyed all Starships they could get their hand on out of hatred.

Yeah what a train wreck. Another fatal flaw not directly related to the canard itself but the pusher layout behind the wheels. Props get chewed to hell by whatever's on the runway (forget about non-paved), and the props can have corrosion issues from the carbon coating from the exhaust (not helped by rock dings that compromise the paint). The Piaggio has the same problems.

@JohnK This happens when management doesn't listen to the engineers. Since Rutan was the son-in-law of the Beech boss, any criticism was forbidden among the engineers. They even had to copy every construction error from Scaled Composites in the original. On the Starship, for example, one wing was half a percent thicker than the other because of sloppy construction at Scaled Composites.

I wasn't aware of Rutan having married into the Beech family and the resulting side effects.  Holy crap.

@JohnK I don't know exactly how his wife is related to Raytheon management but that was the story when I visited Beechcraft to see how the Starship is built (they wrapped a mandril of the fuselage with carbon tape and then cut the perfectly fine fuselage in two to get the mandril out ...) and spoke to the engineers. Another line was "this is the only airplane where bending moment is nonzero already at the wingtips ...".

Burt Ratan's SpaceShipOne is a very odd duck that counts as having "a non-fixed... stabilizer," if you mean "relative to the fuselage," or "fixed", if you mean "relative to the tail boom."

The design features a unique "feathering" atmospheric reentry system where the rear half of the wing and the twin tail booms folds 70 degrees upward along a hinge running the length of the wing; this increases drag while retaining stability.

So while the individual stabilizers are fixed to the tail boom, the tail boom itself is not fixed to the fuselage, and therefore the stabilizers change their orientation relative to the fuselage.
Here it is in the "unfeathered" configuration:

Above image downloaded from Wikipedia.  By Elrondhubble, CC-BY-SA-3.0
And here it is in the "feathered" configuration:

Above image downloaded from Wikipedia.  By Chris857, CC-BY-SA-3.0

The idea seems to have been around for a while. The Wright Flyer used wing warping.


text:
What is a good sight picture for telling urban vs rural areas (wrt minimum AGL)?
I'm studying for PPL and am struggling to imagine a clear "sight picture" for urban vs rural areas with regards to minimum AGL. I found that urban areas are outlined over at the Federal Census Register and are well defined, including

It is urban if it contains at least 4,000 housing units or has a population of at least 10,000An area will qualify as urban if it contains at least 2,000 housing units or has a population of at least 5,000.
Maximum hop distance 0.5 miles, maximum jump distance 1.5 miles, and no hops after jumps. Intervening, low density blocks are not included in the urban area.

Does this basically mean urban is any small town? I.e. not farm, lake, national park, etc?
As a fun side-story: when I was a kid, my grandpa worked with a cropduster that used to "dust" us kids with candy if he saw us playing outside. He was for-sure near minimum AGL.

From high up it's probably easier just to look for farmland and tall buildings (4 floors or more).

I'm struggling to understand the actual question here. Are you asking how to tell a town from a city, or rural areas? Or are you asking what the definition of an urban area is?

As you probably know, 91.119 refers to them as “congested areas” and “other than congested areas”.  Interesting discussion, but zoning such as urban, suburban, rural etc. is academic when it comes to the actual regulation, and it’s really a judgement call to distinguish them while airborne.

The regulations make no reference to "urban" and "rural." It makes reference to "congested," "other than congested," and "sparsely populated." They intentionally do not define these terms anywhere. Per the Anderson interpretation, the FAA determines what "congested" means on a case-by-case basis.
The example listed is that a subdivision .5 miles by .66 miles containing 20 houses counts as "congested." At 60 houses per square mile, that's more than 10 acres per house! That population density is much less than the 500 people per square mile that qualifies an area as rural. And yet, somehow, the FAA and NTSB think this is "congested."
Here is such a congested area, a subdivision near Harwood, ND:

This is actually slightly denser than the hypothetical subdivision described by the NTSB as "congested."
In short, if you have to ask, you should assume the FAA will consider an area to be congested if you give them any reason to be asking about your flight. It's probably best to just treat "sparsely populated" as meaning unpopulated.
Side note: cropdusters operate under part 137. 14 CFR § 137.49 and 137.51 gives them wide latitude to ignore the part 91 minimum altitudes when it is necessary for their operations.


text:
Why don't black boxes have their own GPS?
In too many cases of unfortunate incidents, hunting for FDR (or CVR also) is a major challenge.1 There are many or all answers recorded on that device.
Why a locator (GPS linked) cannot be included in the black box? It has its battery which runs for several days and very rigid outer shell.
Ordinary cell phones are GPS enabled which pinpoint their location with the accuracy of a couple of feet. So why there cannot be a more sophisticated technology added to the black boxes?

1: I am aware that most of FDRs/CVRs are eventually recovered.

GPS is receiving only the satellite doesn't know what devices are getting its signal, to send you location to a receiver you need a radio connection of some kind, if we could do that then we wouldn't need the gps location in the first place

It would not be possible to get the (enormous) power required to transmit something through 5000 feet of water.  Even submarines can't do that and they have something of an advantage over a small box.

First let's and define what "too many cases" means in terms of cold, hard, unfeeling numbers (as best we can):
Wikipedia has a list (admittedly incomplete) of crashes where the CVR/FDR was not recovered. There are 16 crashes listed. I'll further add Air France 447 (which took "a long time" to find), and MH370 (which is currently unrecovered), bringing the total to 18.
As Wikipedia admits their list is incomplete I'll double-and-round that in the name of being pessimistically conservative and say that since 1965 there have been 50 cases where it has taken "a long time" to recover the flight recorders (or they were never recovered).
In a single year there can be over 100 "incidents". Even if we assume the CVR/FDR data wouldn't be useful for all of them there are still many hundreds (if not thousands) of incidents since 1965 where the cockpit voice recorder and/or flight data recorders have been recovered along with other wreckage or damaged airframes - often within a matter of days or hours (as soon as investigators can get to the wreckage). That's a pretty good track record.
One could certainly argue (legitimately) that "one unrecovered flight recorder is too many", and indeed the goal is to always find the recorders and analyze their contents.
If we're being realistic about this though we're going to have to accept the fact that sometimes you're just not going to recover the recorders: Aircraft crashes are messy, high-energy affairs and often involve inhospitable recovery environments like "the bottom of the ocean".

If someone has better statistics close at hand I would love to review them and update this answer. Otherwise, it should be obvious that the above is an extremely rough off-the-cuff estimate, and should not be taken for any research or investigative purposes.
  In case it's not obvious - well I just said it.

Now, to the meat of your question:
Theoretically you could include a locator beacon in the CVR or FDR - incorporating a 406MHz ELT into the black box design is possible (you could even add a GPS to encode the device's location, though it would be of limited additional value with the inherent location accuracy of the 406MHz locator signal and satellite search system).
So why don't we do it?
As Lnafziger pointed out, airliners are already required to carry emergency locator transmitters - in any case where such a beacon would function including one in the CVR/FDR would be redundant with existing equipment in the aircraft.
Further practical problems arise when you consider the kind of abuse a "black box" is subject to -- These things need to survive a crash (up to 3400 Gs), crush forces, fire, and immersion in water under pressure.
Your typical distress beacon requires an antenna and a view of the sky, both of which would be in serious doubt after a crash:  The black box may be inside or under wreckage, required external antennas may have been torn off or burned away, and distress beacon signals are unlikely to be received if the recorder is under water (this is why current generation recorders have sonar "pingers" to assist in locating them).

To easily illustrate the sort of problem radio devices have with "stuff" between them and the sky, try this experiment: Take your cell phone, wrap it in aluminum foil to simulate the skin of a plane, put it in a zip-lock bag, and take it to the bottom of a pool. I bet you won't be able to get a call on that phone.

Given the numerous failure modes (all of which are fairly high-probability in a real-world crash scenario), and the fact that we usually have a pretty good idea of where an aircraft is when a crash does happen, there isn't much to be gained by including additional locator technology in the CVR/FDR designs at this time - it just adds more components that would need periodic testing and recertification to ensure they are functioning properly and would activate appropriately in the event of a crash, while not appreciably improving our odds of finding the recorders.

Thanks for the thorough answer. I agree FDRs are eventually found but many times it takes longer. What I had in mind was a way/technology to announce its position when it could not be located. Using the existing technology, there are many limitations (which you have pointed). Maybe in future someone can invent something which could help tracing objects easier. Of course some people don't like to be "traced" all the time.

If you can receive a signal from the device, then you can already home in on where that signal is coming from. The signal does not need to include the position.
GPS would also be of limited use. In most scenarios, it would probably be unable to receive a signal underneath water, terrain, weather, and wreckage. The GPS and antenna would also have to survive in order to function.

+1 This is the crucial information: GPS doesn't work well in typical crash scenarios. It actually doesn't work at all below a not so thick layer of water (surely no more than couple meters).

To answer this question, you need to understand how GPS works. GPS satellites just keep continuously beaming the time the message was transmitter, and the position of the satellite at the time of the transmission.
The GPS receiver/client then interprets your location based on the transit time of each message and computes the distance to each satellite.
This means, the satellites or anyone other than your GPS receiver don't know your location. To transmit your location to anyone, you need a medium (such as the internet or GSM network), which is absent at the bottom of the ocean.
Source: Wikipedia

Actually, modern 406 Mhz ELT's do have GPS built-in and they transmit their location to satellites when activated.
Since they are required by US regulations, it would be redundant to require the black box to have its own.
From Wikipedia:

GPS-based, registered
  The most modern 406 MHz beacons with GPS
  (US$ $300+ in 2010) track with a precision of 100 meters in the 70% of
  the world closest to the equator, and send a serial number so the
  responsible authority can look up phone numbers to notify the
  registrator (e.g. next-of-kin) in four minutes.
The GPS system permits stationary, wide-view geosynchronous
  communications satellites to enhance the doppler position received by
  low Earth orbit satellites. EPIRB beacons with built-in GPS are
  usually called GPIRBs, for GPS Position-Indicating Radio Beacon or
  Global Position-Indicating Radio Beacon.
However, rescue cannot begin until a doppler track is available. The
  COSPAS-SARSAT specifications say [7] that a beacon location is not
  considered "resolved" unless at least two doppler tracks match or a
  doppler track confirms an encoded (GPS) track. One or more GPS tracks
  are not sufficient.

In the US, ELTs are not required on air carriers (scheduled air carriers), and an ELT is not a FDR. §91.207 http://www.ecfr.gov/cgi-bin/text-idx?rgn=div8&node=14:2.0.1.3.10.3.7.4

@CJBS I never said that an ELT is an FDR, and I had forgotten that it isn't required for scheduled air carrier flights.

You're right, but I think it's somewhat implied -- the question isn't about ELTs, it's about black boxes. Regarding the U.S. FAA not requiring ELTs for scheduled carrier services, it's this crash type that tends to attract the most media attention, most likely hence the question. For what it's worth, I had also assumed that ELTs would automatically be on air carriers too (from GA pilot training), only to be reminded that that's not the case for scheduled services. Doesn't really make sense that they're not required, does it?

@CJBS I know that it isn't about ELT's, but having an ELT negates the need to add one to the FDR, which is what I wrote....

This is true. Presumably the reason that they're not required on air carrier services is that air carriers typically know where their craft are.

"it would be redundant to require the black box to have its own [locator beacon]" And aircraft never have redundant equipment on board!

The answers are missing the point. Some companies have real time GPS enabled tracking on fleet trucks.  You can go on a computer and check where these trucks have been 1 week back. When some of you say GPS signals can't penetrate deep waters, it would have at least sent it's last known coordinates before impact that could have been recorded if there was a system in place to record. Then we could better pinpoint impact areas.

Sent by what mechanism? Tracked trucks are seldom out of cell phone range; intercontinental flights are seldom within cell phone range. And, in any case, all systems on aircraft can be switched off so that faults can be isolated.

@DavidRicherby Sent by satellite is one option...

Completely agree with Thilak.
With a GPS receiver attached to a black box, only the black box will be able to know its own location. We are able to use GPS for tracking assets becuase those devices transmit the location information received from GPS, using various channels such as GPRS or satellite connectivity. In the case of black box -
(a) GPS signals from satellites reaching the receiver is not guaranteed at all places e.g ocean beds.
(b) If the black box did had the channel to transmit GPS information (Which it does not have) to back office, it could rather send much more actual data.


text:
What happens during a checkride for a private pilot license?
For a Private Pilot License in USA, what happens when a student takes his/her checkride? I want to know the sequence of events. According to my knowledge, which is sort of vague, things proceed as follows:

Student takes an oral and written exam (not sure if it's on the same day of checkride or prior to that).
Examiner asks student to plan a cross-country flight.
Examiner and students go for this planned cross-country flight.
Examiner may or may not cancel this plan and ask student to go back (does not affect result).
At the end, examiner tells the student if he/she has passed or not.

What I do not know is:

How much of the above is accurate?
And how long does it take?
How are emergency procedures created and tested?
Who makes sure that the weather is suitable for flying?
What if the checkride has to be cancelled for reasons not controlled by student?
What else did I miss?

Remember: During your check ride, you are the most nervous that you will ever be in your life. ***IMPORTANT - you got this - you studied - your instructor is confident you will pass or he would have not endorsed you - you are flying with a buddy and showing him what you do as a pilot - keep it that simple and maintain that mindset and you will have FUN <- YES FUN!!!! Afterwards you feel as if you could take on the WORLD! Best feeling ever.

That's pretty much the checkride in a nutshell - for all the details on what's expected you should refer to the FAA Practical Test Standards for the rating you're pursuing.
Before your checkride
At some point before your checkride you must take a "knowledge test" (the "written exam") - you must pass that exam in order to qualify to take the checkride (the "practical test").
The results of the knowledge test are good for 2 years.
You will also receive instruction from your CFI specifically for "checkride preparation" (you must have 3 hours of this instruction within the 60 days prior to taking your checkride).
Usually your instructor or school will arrange for an examiner. Be sure to find out where he wants you to plan your cross-country trip to, and also ask for his weight (so you can do the weight and balance calculations), and the cost of the checkride (so you can have the money ready).

The Oral Exam
The day of your checkride1 you'll probably spend at least as much time on the ground with the examiner than in the air.
You'll start with the practicalities: making sure your 8710 is in order, verifying your eligibility, and paying the examiner.
Next, you'll go over your logbook with the examiner (do everyone a favor and bookmark all the things they'll need to see), and then you'll be given a thorough oral grilling2 by the examiner.
You'll be expected to know your aircraft's V speeds, it's useful load, and its fuel capacity (in gallons and hours), and you might have to be able to answer intelligently based on a scenario, like "supposed you want to take 3 members of your football team's lineup on a 300 mile trip..."
There will also be scenario-based regulatory questions ("You're taking your friends for a flight in the spring, but you haven't been in an airplane all winter. What do you need in order to be able to conduct this flight?")
You will also be expected to plan (or have planned, depending on the examiner3) a cross-country flight (including a weight and balance calculation using the examiner's weight, and possibly including one or more fuel stops), and be able to explain your decision-making process for things like the planned course (if you don't fly in an absolute straight line) and your proposed altitude(s) and en-route waypoint(s).
1 - Usually you do the oral exam, then go fly.  Sometimes you may do the oral one day and the flight portion another day - for example if the weather is lousy.
2 - This video is a little old, but a lot of it is still valid.
3 - You used to have to complete the flight plan the day of the exam, within 30 minutes, but that requirement has vanished from the PTS.

The Flight Exam
Every examiner conducts this a little differently - the tasks can be done in any order as long as they're all accomplished - but everyone I know has had the same basic sequence of events on their checkride.
After the oral you're going to get an update to your weather briefing (because you should), do a preflight inspection, get in the plane, and go fly your cross-country.
I've never met anyone who has actually flown the whole cross-country flight -- The examiner will typically have you fly through one or two waypoints to demonstrate that you can actually navigate, then you'll be told that something has gone awry and you need to divert ("The guy in the back is sick, take me to the closest airport before he hurls.").
When you've demonstrated your ability to navigate and divert, you'll usually cancel your flight plan (if you opened one) and break off to do the required air work.
At some point during your checkride the examiner will give you an engine failure, because aircraft engines are supremely unreliable whenever an examiner or CFI is in the right seat. You will be expected to pick a suitable landing point, establish a glide to that landing point, and run the "engine failure" checklist appropriate to your plane.  The engine usually "miraculously restarts" at some point once the examiner is confident you would have been able to put the plane down on your intended landing spot.
The air-work consists of all the require flight maneuvers, such as steep turns, stalls, slips, and slow flight, the required ground reference maneuvers, and basic instrument maneuvers.
Once the air work is complete you'll return to the airport (or maybe to the airport you diverted to) for the dog-and-pony-show landings (one go-around -- usually called by the examiner with something exciting like "There's a moose on the runway! Go around!", one normal landing, one short-field landing over an FAA-Standard 50-foot giraffe, and one soft-field landing).
If you mess up and the examiner has to fail you they will tell you immediately after finishing the maneuver that you busted on. You usually have the option of continuing the test and completing the remaining tasks unless you did something that made the examiner fear for his or her life (if you're comfortable continuing this reduces the number of tasks you'll have to complete when you re-take the checkride).
Assuming you don't screw any thing up too badly, scare the examiner, or hit anything taxiing back to the ramp you're a private pilot - the examiner will fill out the appropriate paperwork, sign your logbook, and issue you your temporary certificate.

Your specific questions that I didn't answer above
How long does it take?
My checkride took about 3-4 hours -- about 1-2 hours for the logbook review & oral, just over an hour in the plane, and about an hour of "miscellaneous bits" (re-briefing the weather, the preflight, securing the plane after the practical portion of the test, completing the IACRA paperwork to make your new certificate/rating official).
How are emergencies created/tested?
The standard engine failure is usually created by pulling the throttle back. Your examiner may throw other curve balls at you (like handing you the foggles and saying "You just flew into a cloud, get us out of it."), or create random distractions ("dropping" their pen during climb-out appears to be a favorite from reading other people's checkride stories).
What's important isn't how the situations arise, but how you handle them.  The examiner wants to see you fly the airplane safely, run the appropriate checklist(s), and handle the emergency in such a way that they're confident if it happened for real you'd be able to do the right thing.
Who makes sure the weather is suitable for flying?
You do! You are acting as Pilot In Command for your checkride, and you are expected to exercise sound judgment.
The examiner is not going to let you take off into a thunderstorm or gale-force winds (examiners have excellent self-preservation instincts. Most of them are or were flight instructors.), but if the examiner has to be the one to say "Yeah, I don't think we should fly in this weather" that's a guaranteed failure.
What if the checkride has to be cancelled for reasons not controlled by the student?
If you've already started (e.g. taken the oral, but can't do the flight portion because of weather, or the plane develops a mechanical problem) you'll receive a "notice of discontinuance" and reschedule the remainder of the exam.
Typically you can do this within 60 days, and you'll only have to do the portions of the exam you didn't do previously (though you can be re-tested on everything).
The same thing happens if you or the examiner have to cancel the exam for reasons not related to your aeronautical performance (that triple-breakfast-burrito on checkride day was NOT a good idea and you need to get back on the ground RIGHT NOW).
What else did I miss?
Probably a lot. I probably missed a lot too.
My checkride wasn't that long ago but I really don't remember much about it.
A common misconception is that the DE will bust you for one deviation or one wrong answer on the oral. That's simply not true. You must perform at an "acceptable level of competence," and only if you fail to perform at such a level will you be failed. The best way to avoid this is to acknowledge the deviation by saying something like "I'm low, correcting," and then correct. That way the DE knows you know what is happening in the plane, and that you are taking positive steps to correct it.
Also, don't think the DE can read your mind. Brief out loud everything that is happening in the plane: annunciate the checklist items, and say "takeoff checklist complete" when you're done; when you scan for traffic or make a clearing turn, say "clearing"; if you see a plane say something like "traffic, 4 o'clock low, opposite direction, no factor." The more you say, the more the DE knows how you think, and aeronautical decision-making is one of the most important skills a pilot must learn.

This is certainly very thorough. I liked the humor references.

@Farhan some of those are direct quotes from the DE who did my checkride - those I remember :-)

The "Before your checkride" portion has other things, of course.  This question covers the requirements in more depth: What are the requirements to take the private pilot check ride?

+1. If it were possible, I'd given an additional +1 for "Aircraft engines are supremely unreliable whenever an examiner or CFI is in the right seat."

they can be unreliable regardless of where she is sitting!

Aircraft engines sound like professional footballers. Supremely fragile until they're helped off the field by the trainer, then sudden, miraculous recovery!

The engine usually "miraculously restarts". Be prepared that this might not happen. On one checkride (not the Basic PPL though) there "miraculously appeared" a private airstrip not marked on the charts and unknown to me, but obviously known to the examiner where we landed. Absolutely terrifying!

You will be examined in 3 ways, written, oral and practical.  The checkride consists of only the oral and practical portions of the exams.  The written is computer based and must have been completed with the 2 years preceding the checkride.
When you complete the written you will get a sheet that is stamped and embossed certifying your score and listing your deficient areas.  You will present this to the designated examiner (DE) that conducts your checkride.
When your instructor recommends you for the checkride, he (or you) will coordinate with the DE and tell you to prepare a cross country flight plan (complete with winds/times/fuel burn for the day of the exam).
When you arrive at the checkride, the DE will being querying your knowledge about the airplane, its limitations, v-speeds, equipment, legality for VFR day/night flight, etc.  He will also query your knowledge on flight planning, weather, airworthiness, navigation, regulations, etc.  The topics of interest are all listed in the Practical Test Standards (PTS) area of operation I.  These questions comprise the oral examination.  This can take anywhere from 1 - 3 hours, depending on numerous factors (your performance, your deficiencies on the written, what checkride this is (initial vs addon vs instructor), etc.
Part of the airworthiness questioning will involve the aircraft logbooks and verifying the airplane is legal for the flight you are about to embark on.
For the practical part of the exam, the DE is going to observe and make notes and give the occasional command or question.  He is not going to coach you.  If he touches the controls, you will get the pink slip.  From the go/no-go decision to the end of flight, you are the PIC and you must demonstrate the ability to perform as one.
You will preflight and perform some variety of takeoff at the DEs discretion and then proceed on your cross country flight.  At some point along this flight you will find the need to divert and will be tested knowing how to calculate time/fuel burn to your new destination based on your present position, as well as properly turning to a heading that will get you there.  Along the way you will do maneuvers.  When you get there you will do some landings and takeoffs.  On the way back home, you will do maneuvers.   The list of maneuvers and how well you need to fly them are in the same PTS document linked above.  This flight will probably be around 2.0 on the hobbes clock.
If at anytime you "bust" the checkride, the DE should tell you immediately and give you the option to go home or continue.  It is in your interest to continue if your nerves haven't got the better of you as if you re-take the exam within 60 days you do not have to repeat successful items.
When you park the plane the DE will go inside while you do the post-flight and when you get inside he will either have a temporary certificate or a pink slip.  If you get the certificate, you are a private pilot.  If you get the pink slip, you get some more instruction and try again.

A great answer. Combining all of them gives a really good picture.

How much of the above is accurate?

You take the written exam before you take the checkride. When you pass the written, the proctor will give you a piece of paper that proves you passed, you need to show that to the DPE before the checkride.
In my case, when I called the DPE to schedule the checkride, he asked me to plan a cross country flight to an airport we both agreed upon. The examiner will review your planning and preflight preparation for the flight but you won't be landing at your destination. Depending on your examiner, he may ask you to divert or simply proceed with other requirements of the test.

And how long does it take?

That depends on the examiner. I believe an hour for the oral and two for the practical flight is common.

How emergency procedures are created and tested?

You should look through the Practical Test Standards book to understand what will be required of you. Expect a simulated engine failure, steep turns, power off and power on stalls, slow flight, etc.

Who makes sure that the weather is suitable for flying?

You do, your examiner will be deferring to your judgement about all aspects of the flight. Weather, aircraft airworthiness, your comfort level, etc. He's looking to see if you'll be a safe pilot and make good decisions about flying. If you don't like the weather then reschedule the checkride.

What if checkride has to be cancelled for reasons not controlled by student?

Then you'll reschedule with the examiner. I've heard of people having to reschedule four or five times before they actually flew the practical test.

What else did I miss?

I know it's easier said than done but: relax! Treat the checkride less as a test and more as your first flight with a passenger. The examiner wants you to pass but they also want to make sure you'll be a safe pilot. Go up with your CFI as many times as needed to feel comfortable and then go up with another CFI in a mock checkride.

I like that you answered each question with your experience also. Thanks a bunch.

I really like the suggestion to perform a mock checkride before the real one.

Adding to the previous answers (very detailed, solid ones, I might add), it's good to ask around about the examiners in your area. They do differ in personality which can affect your experience. The best examiners make you comfortable enough to perform to the best of your ability. In my flying club (which licensed six new pilots this year of of a total of 30 members), most of us went with one DPE. One of the six, however, had some friction with that DPE and got his ticket with one of the other DPEs.


text:
What is the difference between a waypoint and a significant point in an airspace?
I know ATS routes are made up of waypoints, but what are Significant Points used for? Is there a difference, or are they really just two names for the same thing?

Never heard of that term. Where are you seeing it?

Voting to reopen. This question is perfectly clear. It is asking about the difference between two commonly used and very similar terms.

@MichaelHall Significant Point is a defined term. https://ext.eurocontrol.int/lexicon/index.php/Significant_Point

@MichaelHall Example: https://aim.naviair.dk/media/files/213fmv0yw3h/EK_ENR_4_4_en.pdf

@MichaelHall No one said anything about the FAA. Not sure why it matters if it's an FAA term or not.

@MichaelHall nobody confirmed that Significant Point it is not an FAA term. expeditedescent just pointed to a definition. The original source is actually ICAO Annex 11. The USA is an ICAO member, so within the FAA the term Significant Point is probably used as well.

@MichaelHall I can now confirm that the FAA uses the term as well, with a slightly different definition.

@DeltaLima, yep, I found it in the FAA glossary.  Definitions are virtually identical.  I’m still hoping an answer will provide some context because I haven’t heard the term actually used before.

@RalphJ I was reading an EAIP of Singapore and saw it there. It seems Significant points are not a part of the documented air route but a pilot can still be asked to maneuver to or from them.

According to ICAO PANS-ATM (Doc 4444) 16th Edition,
Waypoint is a type of significant point.
Mentioned in Chapter 1 - Definition as

Significant point :- A specified geographical location used in defining an ATS route or the flight path of an aircraft and for other
navigation and ATS purposes.  Note.— There are three categories of
significant points: ground-based navigation aid, intersection and
waypoint. In the context of this definition, intersection is a
significant point expressed as radials, bearings and/or distances from
ground-based navigation aids.
Waypoint is defined as a specified geographical location used to define an area navigation route or the flight path of an aircraft
employing area navigation.

So in short waypoint is a significant point used to define an area navigation route or the flight path of an aircraft employing area navigation

This is the book definition, but they sound very similar to me.  The OP asked "are they really just two names for the same thing?" It would appear to me that they are.  Can you offer a practical example of how they might be used differently?  It would help to have some context.

A VOR reporting point on a conventional ATS route (Non RNAV ) is a significant point but  not a waypoint if it is flown by an aircraft not employing area navigation.

it is a waypoint if you put it in your flight plan and fly to it.  I have never heard anybody ever refer to a point on their flight plan as a “significant point”.  In normal use, if it is in your route of flight it is commonly referred to as a waypoint, fix, intersection, turn point, or NTP, (Nav Turn Point). This is of course based solely on personal experience, so I cannot make any claim beyond 4 decades of flying, mainly in the US.  Other country’s pilots may very well use the term “significant” in normal conversation.

The question was about the difference between these two terms. It doesn't matter whether pilots uses this term in normal conversations. ICAO PANS-ATM uses 'significant point' term whenever the rules or separations are based on either a waypoint or a nav-aid. A nav-aid becomes a waypoint only when you put the nav-aid coordinates in FMS and fly. If an aircraft without FMS  onboard flying by tuning in to  a VOR onboard, then  it's a significant point and not a waypoint and separations methods  mentioned in PANS-ATM for aircraft employing area navigation may not be applied between such aircraft.

Thanks for the additional info.  Sounds like it is more relevant to ATC then.  Perhaps you could add this information to the answer?  And I assume that you provide the different separation based on the equipment code?

@Michael Hall. Separation methods and minima  depends upon the navigational aid and  capability of aircraft especially in non-radar environment. ATC gets alerts and warning from automation systems when an aircraft is not equipped with right equipments for the airspace they are flying. An aircraft having no GPS / VOR board cannot be separated using VOR lateral separation minima mentioned in PANS-ATM even though it is difficult to find an aircraft in such a condition. So there comes the importance of significant points and waypoint.


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What does runaway failure mean (position difference between APPU and FPPU) on A320?
I've been reading the description and operation of Flap systems. WTBs will stop and hold the transmission whenever SFCCs receive some failures.

A runaway failure of an actuator is a situation where the actuator deflects maximally into one of its stops and stays there. Particularly hydraulic actuators can be subject to these: if the servo valve cannot close due to for instance dirt being stuck in the valve, oil flow will cause this type of failure. Electrical actuators commanded by a servo loop can fail in this mode as well.


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How can the zero-lift drag coefficient (parasitic drag) be calculated?
Consider a 3-D wing made from an arbitrary airfoil, say a NACA0012 airfoil. The wing has a trapezoidal shape, with a fixed span, root chord, and tip chord. Also, assume that the wing loading is known as well. I am trying to calculate the speed at minimum drag of this wing (assume that there are no other parts of the aircraft, just the wing!) My thought process is as follows:
We know that, to a reasonable degree of accuracy, that there are two types of drag on the wing in steady, level, flight: parasitic drag and lift-induced drag. This can be shown mathematically as:
$$ C_D = C_{D_0} + C_{D_i} = C_{D_0} + \frac{C_L^2}{\pi e AR}$$
Also, assume that the AR and efficiency factor are known. Now, for minimum drag to occur, there has to me a maximum lift to drag ratio. The formula for drag is
$$ D = \frac{1}{2} \rho V^2 S C_D = \frac{1}{2} \rho V^2 S \Big(C_{D_0} + \frac{C_L^2}{\pi e AR}\Big) = \frac{1}{2} \rho V^2 S C_{D_0} + \frac{\rho V^2 S}{2\pi e AR} C_L^2$$
Lift has a similar formula to drag, and in steady, level flight, is equal to the weight of the aircraft. Lift is related to the lift coefficient as $L = \frac{1}{2} \rho V^2 S C_L$. So we solve for the lift coefficient as follows.
$$ C_L = \frac{2L}{\rho V^2 S} = \frac{2W}{\rho V^2 S}$$.
Plugging into our original formula, we obtain
$$ D = \frac{1}{2} \rho V^2 S C_{D_0} + \frac{\rho V^2 S}{2\pi e AR} \cdot \frac{4W^2}{\rho^2 V^4 S^2} = \frac{1}{2} \rho S C_{D_0} V^2  + \frac{2W^2}{\pi e AR \rho S}\frac{1}{V^2}$$
This is great for us, because now we have a relationship between drag and lift, and to find the speed at minimum drag, all we have to do is take the derivative and set it equal to 0. I've done this and the resulting answer comes out to be
$$V_{md} = \Bigg( \frac{4W^2}{\rho^2 S^2 \pi e AR C_{D_0}} \Bigg)^{1/4},$$
where the 'md' stands for minimum drag. My problem arises because I cannot for the life of me figure out how to analytically calculate $C_{D_0}$. It can also be shown that at minimum drag, $C_{D_0} = C_{D_i}$ so that the total drag coefficient becomes $C_D \equiv C_{D_0} + C_{D_i} = 2C_{D_i} = \frac{2C_L^2}{\pi e AR}$, but then we are back to our starting point, which confuses me again.
My last resort was to read some papers that said that there is a method to finding $C_{D_0}$ using the skin friction coefficient, because at subsonic speeds, a large part of the parasitic drag is due to skin friction (and a little due to pressure drag). Anyways, this led me to the formula $C_{D_0} = C_{fe}\frac{S_{wetted}}{S_{ref}},$ where you use an equivalent skin friction and wetted area. Now I don't understand what a wetted surface area is, since in this example we are only dealing with one wing (would it just be twice the regular area??) As you can see, I am greatly confused. How do you find this zero-lift drag, and subsequently the minimum flight speed.

Related

Yes, the wetted area is roughly twice the reference area. Now details depend on how well the reference area captures the exposed area of the wing - dihedral will already increase the wetted area by a factor proportional to the inverse of the cosine of the dihedral angle.
But there is more. Airfoil thickness means that the air has to flow around the airfoil. This displacement effect causes the flow around a thick airfoil to speed up more than around an equivalent but thinner airfoil. The thicker airfoil pushes the air aside and around itself more, causing the flow to accelerate and create more friction than the slower flow around a thinner airfoil. This effect is normally approximated with an additional term in the friction drag formula which is proportional to relative thickness.
Next, the type of boundary layer flow needs to be known. Rough surfaces or high sweep angles will provoke an early transition from laminar to turbulent flow. Read this answer for a more detailed discussion.
Another correction is needed for the Mach number, even in subsonic flow. Of course, once flow becomes transsonic or supersonic, wave drag needs to be added, too.
First you need to calculate the friction coefficient which depends on the Reynolds and Mach numbers of your airfoil flow and the relative mean roughness R:
$$c_f = \frac{\frac{0.43}{log(100/R)^{2.56}}-\frac{1700}{100/R}}{\sqrt{1+0.14\cdot Ma^2}}$$
Next, you approximate airfoil drag as explained above:
$$c_{d0} = c_f\cdot \left(2 + 4\cdot\delta + 120\cdot\left(\frac{1}{\sqrt{1-Ma^2}}\right)^3\cdot\delta^4 - 0.09\cdot Ma^2\right)$$
where $\delta$ is the relative thickness of your airfoil.
The term $\frac{1700}{100/R}$ in the friction drag equation allows for the initially laminar boundary layer. Change the factor 1700 depending on how much laminarity your airfoil offers. This answer shows a graph with the possible range. In the airfoil zero lift drag formula you see first the factor 2 which accounts for the fact that the wing has two sides. To that you add the thickness summand to allow for the displacement effect. The third term with the Prandtl-Glauert factor shows that the formula only works well for Mach < 1, and both the third and fourth term are empirical factors to improve accuracy over Mach.

"..you add the thickness summand". Could not think of a suitable replacement word for summand.

$C_{D_0}$ depends on a whole lot of parameters and is usually measured in a wind tunnel, or determined with Computed Fluid Dynamics. Reynolds number, Mach number, surface roughness, wing taper, wing twist, sweepback angle etc. make the computation of $C_{D_0}$ a bit of an impossibility with analytical mathematics alone.
This answer has some comparison graphs of 2-D data on NACA 0012 at different Reynolds and Mach numbers. Helicopter blades often use symmetrical airfoils like NACA 0012 and 0015 to eliminate twisting moments which would torque the blade.

so how would I be able to solve for the minimum flight speed?

The minimum flight speed is at maximum $C_L$, where the wing stalls.


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What is the most efficient symmetrical airfoil shape?
What is the most efficient symmetrical airfoil shape to make for a covering for a round upright bar that measures 40mm outside diameter?
The speed of travel will be 25Kph and I also need a shape to travel at 30Kph. I assume these will be different to some extent?

Hello JJayes, welcome to aviation.stackexchange. How do you measure efficiency? Lowest weight? Lowest weight / lift ratio? Highest lift / drag ratio? Lowest drag at 0 lift? in other words, what are you trying to achieve?

Do you actually want to generate lift with this airfoil or do you just want to minimize drag?

Hi, I am looking for a tube to be shaped to pass through air in a upright position while travelling at both 25kph and another st 30kph. I do not require any lift. The tube needs to be 40mm in width. I need it to provide the least possible drag. The weight is not a issue.

Truncation (chopping off the rear portion of the airfoil) does not reduce drag, although reducing up to 20% of the chord does not significantly increase it.  As Peter says, "trade off between more separation and more wetted surface area.  Hence "boat tail" bullets.
The 3:1 ratio of chord to width is apparently a bike racing specification.  Nothing new here,
the full airfoil produces the lowest drag.  Hence the cone they put on the back of the Space Shuttle while it was piggybacked on its 747.
What they did to meet the 3:1 specification was to truncate 66% of a 9 to 1 airfoil.
This produces the lowest drag within the specification.
The Kamm tail shape was designed for automobiles, providing a weight savings (as racers constantly accelerate and deccelerate) and to make the vehicle a little shorter, which can help changing lanes in a crowd.  Two different applications.  But a fully symmetrical airfoil, such as the struts of a Cessna 172 will do the job.
For an aircraft strut, if strength allows, make it as long and thin as possible until drag values begin to rise.  9 to 1 rings a bell from boat hull design, and would be a good place to start.

This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post. - From Review

9 to 1 ratio thickness to chord added.  Wind tunnel test for specific application may be best.

This site discusses tube width and length ratios for least drag
https://bikerumor.com/2011/04/14/scott-f01l-aka-f01-finally-released-to-the-public/
https://www.bikerumor.com/wp-content/uploads/2011/04/Airflow-tubing-visual.png

Tyler just had a chance to speak directly with Scott regarding the final profile, and reported back that they found that a 9:1 ratio profile with a truncated tail was indeed the fastest, lightest, and most stiff. According to Scott, Scott Aero Science engineers began with various tubing shapes first in CFdesign programs to identify shapes before producing prototypes that would then be validated in the wind tunnel. Over 100 hours of wind tunnel validation time was invested solely in the F01 project using Drag2Zero facilities in Mercedes-Benz Grand Prix Wind Tunnel. Starting with raw tubes, shapes were identified and built into complete test mules, and then analyzed against current competitor designs. Over 60 tube shapes were tested in order to identify the optimum “cut ratio”. The engineers selected tube shapes that are wider than normal NACA aero tubes. They were designed with a “leading edge” and a ratio of height to width that complies with UCI regulations, while still maintaining the lowest air disturbance vis-àvis both individual tubes and the overall frame structure. The ratios of the aggregate tubes are between 6:1 and 12:1 resulting in a 9:1 average ratio, well within the UCI limits and actually going the opposite direction in relation to other manufacturers in this regard. The result is a virtual tube shape, a tube that is not NACA shaped but a truncated cross section, which acts in the same way. Each and every tube in the frameset is analyzed for cut position along the “chord”, or length of the tube profile. Most tubes are cut retaining between 25-35% of the overall chord length. This science of tube shape is a contrast to the Kamm tail designs that emerged 80 years ago in the auto industry in that we use the leading edge of the tube rather than simply cutting the trailing edge like some competitors practice.

Here's another site discussing the same shape.
https://www.trekbikes.com/us/en_US/inside_trek/kammtail_virtual_foil/

While the idea of using bike profiles is very good, the Kamm tail has to meet the 3:1 length to width ratio of the UCI. Less truncation will lead to even lower drag.

30 kph = 18mph, so it seems fitting.  "round upright bar" sounds like a bike vertical bar, as does 40mm diameter, about 1.6". Kamm tail may allow enough drag reduction while being truncated could help on overall weight.

Yes, truncation is a tradeoff between more separation and more wetted surface area. I would expect that some truncation is beneficial and will lead to the overall optimum. But not a 3:1, more a 5:1 ratio - however, that is just a guess.

Hambini roasts the kamm tail virtual foil and explains why, from a cfd and engineering perspective, that it is simply not as aero as a full airfoil. https://youtu.be/QqX3juRttP4
I always am skeptical of the self-reported research from bike manufacturers, especially when they don’t share their raw data and testing methods with the public.


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Can an aileron stall in-flight?
Horizontal stabilizers stall, so I was wondering, is it possible for an aileron to stall? If yes, at what angle of attack?

The equivalent of the horizontal stabilizer (which is a wing) is not the aileron but the main wing. The aileron (a flight control surface) is the equivalent to the elevator (also a flight control surface attached to the horizontal stabilizer)

Ok, So can they stall(elevator and aileron)?

@DavidTeahay As John says, you can't view the aileron in isolation because all it does is modify the wing. But the wing can of course stall - this being the most common type of stall.

Ok,understood....so  at what angle of aileron deflection does an aileron start to create less lift more drag,at what angle does it become inefficient... @Dan

The aileron itself doesn't stall, being part of the main wing.  But since it alters the camber of the main wing it changes the local angle of attack in effect.  On older airplanes, a down aileron at low speed could trigger a stall separation of the wing in the area of the aileron and if you applied aileron to correct a wing drop at the stall, it would just speed things along and over you go.  This was one of the reasons for slots in front of the ailerons on airplanes like the Globe Swift.
Not sure how it is taught today (I learned to fly in 1975) but long ago pilots were always taught to avoid aileron input close to the stall and keep wings level with rudder, although on modern airplanes with washout and other features to delay stall near the tip you can generally get away with it.

Nothing has changed. Aileron neutral in a stall is how to prevent a spin due to adverse yaw caused by down aileron deflection.

Okay....understood.....but what's the maximum angle  that I can deflect ailerons@ Jonh K

@DavidTeahay It's not at all about deflection and you really shouldn't think in those terms. Typical critical AoA is around 15-20degrees against the relative airflow.

@David Teahay you are thinking way too hard.... In normal flying it's not an issue.  But if you find yourself just above stall speed somehow in some situation, you should have been trained to avoid large aileron inputs until you've gained some speed.  There are no published limits of any kind, just good judgement and airmanship.

Your advice for flying close to stall is still sound, and washout is really not a modern feature. Physics hasn't changed, and the aircraft engineers half a century ago were at least as competent as those of today. +1

Well as an old timer, when I say "modern" I mean, oh,  post 1940 lol ;)


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It is possible for an airplane to get infested by animals?
Is it possible for an airplane to become infested by animals like mice or rats?
Is it possible for them to survive?
Do airliners do anything to prevent a scenario like this?
Has it ever happened before?

While there are some great answers below I think it's worth mentioned that it is common for airliners arriving and departing countries such as Mexico to spray insecticide throughout the cabin to stop the spread of insects and disease.

Stinging insects are the main problem. More than one pilot has started up an aircraft that lay dormant for a while only to be attacked by a bevy of angry wasps. Whenever an aircraft is used for the first time in several months, it is a good idea to check it very carefully for wasp nests. I actually have a flashlight and I open the inspection panels and look inside the hidden areas of the fuselage.

it seem a problem only for small, not in use, airplane. I wonder what can happen if a couple of mice enter in an airplane the sike of an a380.

Yes, and they can bring down aircraft too.

Yes, I have personally worked on multiple aircraft that were infested by animals.
All of these aircraft were small planes, single engine Cessnas for example. A typical example would be one or two small mouse nests in the wings. I also found at least one wasp nest in an aircraft wing.
The worst I ever saw was a Mooney that had extensive mouse nests throughout the airframe. That aircraft had been unairworthy for at least a year by the time I saw it.
That Mooney ended up being parted out and scrapped, largely because of extensive corrosion in the wings which was either caused by, or aggravated by, the mouse nests. Urea can induce corrosion in aluminum, and finding a mouse nest or other evidence of rodent activity should prompt closer inspection. All the other instances of mouse nests that I have found in airframes were in aircraft that flew several hundred hours a year and these did not suffer any major damage.
I have also heard stories from many pilots and mechanics of finding birds nests—for example in engine intakes or the empennage—and of rodents chewing into or through electrical wiring. There is also the classic warning to check the pitot tube in case a mud wasp has clogged the intake with a nest. I have never witnessed any of these occurrences myself.
The mud dauber wasp is notorious and is suspected of being a contributing factor in at least one fatal airline accident that I am familiar with: Birgenair Flight 301.

Photo source, courtesy of the FAA
Many means of prevention are available, including typical pest prevention methods such as traps and poisons—in my experience all reserved for use in the storage hanger. The most aviation specific forms are the various covers used to protect pitot tubes, engine inlets, etc.

Photo source, courtesy of the FAA
As far as the possibility of animals surviving, I suppose the odds are low. I have never encountered a live animal in an airplane (pets excepted). For any animal stowing away on a pressurized aircraft operating at high altitude I should think the low oxygen partial pressure and temperature would both discourage survival outside the pressure vessel.
Some flights, particularly international ones, apparently make a practice of spraying some form of pesticide in the cabin to kill mosquitoes and other unwanted creatures.

Birds trying to nest in the engine compartment are not unusual, so much so that in the spring a normal part of the preflight for my Cherokee was to take off the upper cowling to check for nestbuilding.

Do you know of any "mouse chewed through rudder cable" accidents?

@TomMcW I've never heard of that. Rudder cables (any control cables for that matter) are usually fairly sturdy; I can't imagine a rodent making much headway on those. I have seen corroded rudder cables that were starting to fray, and I suppose a very determined animal might make a little headway if the cables were particularly rotten. But then the rodent would only be contributing to a pre-existing problem.

Birds also like to make nests in the tail cone, so I always check there too in the spring.

@JScarry That would be included in the empennage by my reckoning.

@Jonathan Yep. Birds like to sit on the VOR antennas so there is often bird crap on the empennage as well. jamessqf mentioned that he’s found bird nests in the engine. Like james, I’ve also found bird nests in the engine and as well as the tail cone. And wasps. Wasps frequently get into the cabin, engine, and nose cone. Once, someone forgot to close the vents and a bird got into the cabin and couldn’t get out.

Yes! As Jonathan Walters stated in his excellent response, this is entirely possible. I can't say which airline I work for, but last summer we had a rash of aircraft (I think 5 in one week) that had rejected takeoffs or air turn backs for erratic airspeed indications. As it turns out, those nasty little dirt daubers (mud wasps?) loved the height of the pitot probe on this particular type of aircraft, and the diameter of the entry hole. They were quick too as standard procedure was to pull the covers off 1 hour prior to flight.
I've heard of mouse and rat infestations, but have been fortunate enough to never have had to work on an airplane with such a problem. Again, as Jonathan Walters pointed out, they will chew through wiring like it's their favorite food, from what I'm told.
As an aside, the standard operating procedure for animal infestations (inside the pressure vessel) is to close the aircraft up entirely and fill it with an inert gas (nitrogen, I think) - depriving any animal in the aircraft of oxygen. As I recall, the process isn't quick, but it is very effective.
Finally, sharing a funny story... About two years ago, a plane came in with, I kid you not, a writeup for "Snakes on the plane." Somehow, I'm not quite sure how, two baby pythons managed to get into the aircraft. This, of course, cascaded into every possible Samuel L. Jackson quip and quote you could possibly imagine about snakes being on an airplane. I'm not entirely certain how the flight crew discovered it, but I must admit, if there was a  cockpit camera, we would have surely reviewed the tape on that one!

It is not only possible to survive, it makes their life more comfortable.
I know of several gliders which were taken over by mice. One I cleaned out myself, a Grob 103 Twin Astir. The mice went up through the opening of the tailwheel, climbed up the whole length of the vertical tail and made the inside of the horizontal tail their living room. The small compartment at the nose of the tailplane, which is separated from the main volume by a web, became their restroom.
But they did not sleep on the bare glassfiber. They went up into the cockpit and gnawed on the seatbelts to extract fibers for their nests. I had to replace the seatbelts, but I doubt I got all of the nesting material removed from the hard-to-access inside of the tail. At least the "restroom" was easy to clean ...
The mice moved in in late fall, after we had parked all gliders in a hangar for the winter break. I discovered the infestation only in spring, when I checked the airplane for flightworthyness.


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Navigation theory for Private pilot
Can someone help me explain what is the magnetic bearing, heading and track, please?

Magnetic Bearing:
This is the direction of the plane's nose relative to magnetic north at the plane's current position. Simply stated, it's the bearing that your plane's heading indicator gives you. It's from 000 to 359 degrees(where 000 is north, 090 is east, 180 is south and so on). ATC directions are also given usually in magnetic bearings. Most aircraft heading indicators give reading in magnetic bearing only. Note that bearing is always stated in 3 digits.
Magnetic heading/heading. Same as magnetic bearing.
Track:
This is where things get a bit complicated. Suppose your plane is flying with its nose pointed at 090 degrees(east). You also have a wind blowing in from 000(north). This 'blows' the plane to the south a bit. Now even though your plane is pointed towards east the direction of its flight path is different! This is where track comes in: it's the direction of the flight path of the plane. In some cases it may be the same as magnetic heading (no winds etc), in others it might be different (crosswinds).

Usually you refer to bearing as the magnetic direction to something. From the FAA Glossary "The horizontal direction to or from any point, usually measured clockwise from true north, magnetic north, or some other reference point through 360 degrees." We generally talk about the bearing to an airport, VOR, or waypoint—not to magnetic north.


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What is the heaviest payload ever carried by a single main rotor helicopter?
What is the most heavy payload ever carried by a single main rotor Helicopter?

Largest by volume or weight?

The MIL MI-26 can carry more than 20 tons, including the recovery of the Chinook in Afghanistan. It is the most powerful production helicopter in the world, and holds the record for lifting to 2000 meters of 123,153lbs (including the aircraft). The Chinook on the other hand is only rated to about 10 tons (20,100lbs or so).

Some load is very flexible, e.g. water for fire fighting, concrete for Chernobyl, so it's safe to assume the largest helicopter has been used to it's full capacity, if not overloaded occasionally.

Related answer